Useable style loader does not work after build

[kirill-konshin]

This issue is a:

• Bug report

NWB version is 0.18.6.

If NWB is used with useable styles loader it works well in dev mode but throws an error if build is served.

Setup:

nwb.config.js

module.exports = {
    type: 'react-app',
    webpack: {
        rules: {
            'sass-style': {
                loader: 'style-loader/useable'
            }
        }
    }
};

src/index.js

import React from "react";
import {render} from "react-dom";
import style from "./index.scss";

style.use(); // <----- this line will produce error in build version

const App = () => (<div>Foo</div>);
render(<App/>, document.getElementById('app'));

src/index.scss

body {
    color: red;
}

Steps to reproduce:

1. Build
2. Serve as static
3. Open browser
4. Observe error: index.js:6 Uncaught TypeError: t.n(...).a.use is not a function

[insin]

nwb uses ExtractTextPlugin to extract CSS in builds.

According to these issues you can't extract usable styles:

• https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/25
• https://github.com/webpack-contrib/style-loader/issues/49

If you need to disable use of ExtractTextPlugin in builds, I could add setting webpack.extractText config to false as a way of disabling it.

[kirill-konshin]

you can't extract usable styles

Totally makes sense

Previously it used to work w/o extra config... but if you can add a way of disabling this, please go ahead.

I think that webpack.extractText: false|null should be just enough: a strict check that if it's defined and is falsy then disable the plugin, but undefined will just use default config.

[insin]

If it used to work and the stylesheet was in a split chunk you could try webpack.extractText = {allChunks: false} config - the default was changed to true a while back to avoid pulling the style-loader runtime into every build.

[kirill-konshin]

Yep, that's the case, it is working with allChunks: false. That's a very bad change, it's backward incompatible... I understand the rationale, but still...

In any case, I hope to see a setting to completely disable the extract text plugin because for useable styles case it is useless.

[kirill-konshin]

What will be the ETA of change?

[kirill-konshin]

Fix confirmed.